Task.WaitAll and Exceptions

I have a problem with exception handling and parallel tasks.

The code shown below starts 2 tasks and waits for them to finish. My problem is, that in case a task throws an exception, the catch handler is never reached.

        List<Task> tasks = new List<Task>();
        try
        {                
            tasks.Add(Task.Factory.StartNew(TaskMethod1));
            tasks.Add(Task.Factory.StartNew(TaskMethod2));

            var arr = tasks.ToArray();                
            Task.WaitAll(arr);
        }
        catch (AggregateException e)
        {
            // do something
        }

However when I use the following code to wait for the tasks with a timeout, the exception is caught.

 while(!Task.WaitAll(arr,100));

I seem to be missing something, as the documentation for WaitAll describes my first attempt to be the correct one. Please help me in understanding why it is not working.